Development of Advanced Remote Cutting Technology for Reactor Internals Segmentation - 18274
Since the Three Mile Island decommissioning in the 1980's, Westinghouse has been involved in dismantling and segmentation of commercial reactors. With dozens of components segmented and packaged across the globe, Westinghouse has continued to evaluate the state of the art cutting technologies for their applications in the nuclear industry. While there have been well documented issues of certain cutting technologies in field applications, there are advancements of these technologies which prove them applicable for specific areas of the decommissioning process. During 2017, Westinghouse embarked on a revision of its plasma arc cutting (PAC) technology as part of an extensive innovation program for reactor internals segmentation. While these systems were used in Yankee Rowe and Three Mile Island, new plasma arc cutting systems improve the versatility and have much better precision of cutting. While bringing this technology into the future, Westinghouse is adapting the mounting and application so that it is compatible with the existing mechanical cutting portfolio. This means that in the event that a mechanical cutting technique is unable to perform as intended, a plasma cutting alternative will be available with minimal time to switch cutting methods. A test program for underwater PAC was performed, and the test gave a good reference of cutting speed and handling in different plate thicknesses which can be used when evaluating the use of the new cutting technology for future projects. PAC technology has proven that it could have a future in reactor vessel internals segmentation projects as a complement to the existing mechanical cutting methods under water. Thicknesses up to at least 25 mm can be cut with a much higher speed than the existing mechanical cutting methods in use. This and other cutting technology developments as part of the innovation program provide exciting new possibilities for dismantling and segmentation projects. While each of the techniques presents definite benefits for operators and, more importantly, customers, there are risks that need to be mitigated through engineered processes and controls. (authors)